Nonwoven fabrics with advantageous properties

Abstract

This invention relates to nonwoven fabrics with advantageous characteristics and the method to produce these fabrics. Advantageously, the fabrics of the subject invention have increased thickness (loft) compared to conventional nonwoven fabrics and have high air permeability and open space while maintaining softness and strength at the same basis weight.

1. A nonwoven fabric comprising:
 a first plurality of round and multilobal polymeric filaments having a first denier of between 0.5 and 15; 
 at least about 25% of a second plurality of round and multilobal polymeric filaments having a second denier of between 0.5 and 15, the second plurality of polymeric filaments comprising at least 5% of the round polymeric filaments of the second denier; and 
 wherein said second denier is at least 1.5 times greater than said first denier, at least one of said first and second plurality of polymeric filaments including a polymer selected from the group consisting of nylon, polypropylene and polyethylene. 
 
     
     
       2. The nonwoven fabric according to  claim 1 , wherein said second plurality of filaments have a denier of at least about 10. 
     
     
       3. The nonwoven fabric according to  claim 1 , wherein said fabric comprises a basis weight of between about 0.2 ounces per square yard and about 7 ounces per square yard. 
     
     
       4. The nonwoven fabric according to  claim 1 , wherein said fabric comprises a basis weight of between about 0.2 ounces per square yard and about 0.6 ounces per square yard. 
     
     
       5. The nonwoven fabric according to  claim 1 , wherein the filaments of said fabric are autogenously bonded to one another at discrete points throughout the fabric. 
     
     
       6. A nonwoven fabric produced by a method comprising the following steps:
 a) providing a first plurality of polymeric filaments having a first denier of between 0.5 and 15 and a second plurality of polymeric filaments having a second denier of between 0.5 and 15, wherein said second denier is at least 1.5 times greater than said first denier, at least one of said first and second plurality of polymeric filaments including a polymer selected from the group consisting of nylon, polypropylene and polyethylene; 
 b) directing the first and second plurality of filaments onto a collection surface to form a web; 
 c) mixing the first and second plurality of polymeric filaments to form a nonwoven fabric comprising at least 25% round and multilobal filaments of the second denier, the second plurality of polymeric filaments comprising at least 5% of the round polymeric filaments of the second denier; and 
 d) forming a multiplicity of discrete bond sites in the fabric to bond together said filaments. 
 
     
     
       7. The nonwoven fabric according to  claim 6 , wherein the fabric comprises a basis weight of between about 0.2 ounces per square yard and about 0.6 ounces per square yard. 
     
     
       8. The nonwoven fabric according to  claim 7 , wherein the filaments are made from nylon. 
     
     
       9. The nonwoven fabric according to  claim 6 , wherein said second plurality of filaments have a denier of at least about 10.